<script src="vue.js"></script>

<div id="app1">
    app1:{{title}}
</div>

<div id="app2">
    app2:{{title}}
</div>

<script>

    var Vue2 = Vue.extend({
        data() {
            return {
                title: "vue2Title"
            }
        }
    })

    var vu1 = new Vue({
        el: "#app1",
        data: {
            title: ""
        }
    });

    var vu2 = new Vue2({
        el: "#app2",
    })
</script>